Marie: “I’ll be there on Saturday. It’ll give me a chance to have a butcher’s at the hundreds of photos of Su’s 40th.”
Butcher’s = Butcher’s hook = look

If you’ve lived in England for any length of time, you’d have picked up one or two pieces of slang that keep you safe on the 157 nightbus from centre of town at 3 in the morning… So this was pretty funny to read ;-)